A differential pressure controller with a pressure chamber divided into two by a moving partition has for each part-chamber one outlet and one inlet valve for the medium to be controlled. Each inlet valve has a sliding fit between a guide part and a sliding part which can be axially moved with the moving partition, the length of which sliding part, which determines the flow resistance, depends on the axial position of the sliding part. Deflections of the partition due to an unwanted differential pressure result in a change in the flow resistance in the inlet valves which counteracts the cause and leads to the pressure compensation aimed for. <IMAGE>
